Interactions of bovine serum albumin with mucin during pH cycling

Abstract

The aim of this study was to characterize the diverse molecular interactions in a model system consisting of mucin which is the main viscosity enhancer of biological fluids, and BSA in a pH range of 5-9 and in various ratios of 10:0, 8:2, 6:4, 5:5, 4:6, 2:8, 0:10 of the 2 components. The mixture of mucin and BSA in a ratio of 8:2 (w/w) under acidic pH 5 led to form visible aggregates explaining also the separation of the 2 phases. At pH values of 7 and 9 the mucin redissolved due to the existence of electrostatic interactions. The viscosity of the mixtures decreased with increasing shear rate regardless of the pH value and the ratio of the 2 components in the mixture. The findings of this study highlighted the importance of understanding the physicochemical basis of the food system followed in special diets and the importance of regulating the functionality of these food systems.